Clamp or anchorage



internally threaded to receive the corresponding threads M of a hollow or axially bored set screw l5, one end of which has a head it to receive a rotating tool or wrench for forcefully advancing the inner end ll of the set screw into the bore l3. The axial bore l8 of the hollow set screw is internally threaded at H] to engage the threads 20 of a pressure screw 2 I. The head of this pressure screw is adapted to receive a wrence or rotating tool, whereby the screw may be driven through the set screw bore and toward the conductor end 9. The lower end of the presure screw is indicated at 22.

The pressure screw 2! is adapted to drive very forcibly against and between the conductor strands, a mass of deformable material such as lead or any soft or ductile metal having the property of electric conductivity, and the ability to fill the voids or spaces between the conductor strands, thereby to increase the density of the conductor within the confines of the body bore 8. The mass of deformable material initially may be in the form of a slug 23 having a head 24 and a shank 25, or alternatively, it may consist of simply a cylindrical short bar or rod as indicated by the character 23A of Fig. 5. In either case, the slug will extend at least partially within the axial bore IQ of the set screw, so that the advancing force of the pressure screw may be applied to the slug for driving it forcefully against the conductor and dispersing the material thereof throughout the voids and spaces between the conductor strands. Because of the reduced diameter of the pressure screw and the limited area of its advancing end 22, a very powerful force is available for deforming the slug and causing it to flow through the interstices of the conductor. This action of the slug material literally expands the conductor within the body bore 8, increases its density to a maximum degree, and thereby enhances the current conductivity property of the connection without mashing, mutilating, and weakening the conductor strands. A connection so made will obviously be mechanically strong and very tight, and will remain so, resulting in great dependability of the connection indefinitely. The possibility of destructive arcing and heating of the connection is thereby completely overcome, this being a consideration of primary importance to the invention.

While in the foregoing explanation it has been made to appear that the advancing end of the pressure screw may bear directly upon the deformable slug 23 or 23A, some advantage may be realized by interposing between these elements a sealer disc 2'! of hard non-deformable material, the function of which is to minimize any tendency for the slug material to creep or extrude upwardly along the threads of the pressure screw during the clamping operation. The sealer disc may be of metal, or any hard material which will not fracture or disintegrate under the force of advancement of the pressure screw. The disc should preferably fit rather snugly within the set screw bore 89, as will be appreciated. The disc, of course, is slidable within said bore and advances with the pressure screw.

In Fig. 4, the invention above described is shown applied to a bus bar clamp consisting of the clamp plates 28 and 29 movable toward one another by tightening the nuts 30 upon the screws 3|. The body of this clamp is indicated at 32 and carries a plurality of perforated ears or lugs 33 bored and internally threaded to receive the screws 34 which clamp a. cover 35 onto the body.

The screws 34 pass through perforated ears or lugs 36 of the cover. When the cover is applied to the body and tightened down by means of the screws 36, the concave elongated pad 38 initially clamps the bared end of a conductor 31. Cover 35 is supplied with a set screw and pressure screw arrangement l'6A2lA like that of Fig. 2, which performs as an auxiliary compressor and lock to efiect the tight current conductive connection as previously described herein.

The purpose of the Fig. 4 disclosure is to indicate that the means of the invention may be applied to various forms of terminal devices which require secure connections of the character herein disclosed. Accordingly, it is to be understood that various modifications and changes in the structural details of the device may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. In a device of the class described, the combination of a rigid metallic body having a passageway to accommodate a portion of a member to be anchored, said body being bored transverse ly of the passageway intermediate the ends of the latter, a screw thread formed internally of the bore, a set screw having external threads engaging the threads of the bore, said set screw having an axial internally threaded bore, and a head exposed exteriorly of the body to receive a wrench, a pressure screw having external threads to engage the internal threads of the set screw, 2. head on the pressure screw extending beyond the head of the set screw for reception of a wrench, and a slug of deformable material in the set screw bore to be advanced against the member to be anchored by rotation of the pressure screw.

2. In a device of the class described, the combination of a rigid metallic body having a passageway to accommodate a portion of a member to be anchored, said body being bored transversely of the passageway intermediate the ends of the latter, a screw thread formed internally of the bore, a set screw having external threads engaging the threads of the bore, said set screw having an axial internally threaded bore, and a head exposed exteriorly of the body to receive a wrench, a pressure screw having external threads to engage the internal threads of the set screw, and a head on the pressure screw extending beyond the head of the set screw for reception of a wrench, a slug of deformable material in the set screw bore to be advanced against the member to be anchored by rotation of the pressure screw, and means interposed between the slug and the advancing end of the pressure screw, to block dispersal of the slug material along the pressure screw threads in the direction of the screw heads.

3. In a device of the class described, the combination of a rigid metallic body having a passageway to accommodate a portion of a multiplestrand cable to be anchored, said body being bored transversely of the passageway intermediate the ends thereof, a screw thread formed internally of the bore, a set screw having external threads engaging the threads of the bore, said set screw having an axial internally threaded bore, and a head exposed exteriorly of the body to receive a wrench, a pressure screw having external threads to engage the internal threads of the set screw, and a head on the pressure screw extending beyond the head of the set screw for reception of a rotary tool, and a slug of deformable electric current conducting metal in the set screw bore, to be advanced by rotation of the set screw and dispersed thereby throughout the spaces between the cable strands, for increasing the effective density of that portion of the cable which is within the passageway, thereby to effect a tight and solid anchorage and a low resistance electrical connection between the metallic body, the cable strands, and the interspersed deformable metal.

4. In a device or" the class described, the combination of a rigid metallic body having a passageway to accommodate a portion of a multiplestrand cable to be anchored, said body being bored transversely of the passageway intermediat the ends thereof, a screw thread formed internally of the bore, a set screw having external threads engaging the threads of the bore, said set screw having an axial internally threaded bore, and a head exposed exteriorly of the body to receive a wrench, a pressure screw having external threads to engage the internal threads of the set screw, and a head on the pressure screw extending beyond the head of the set screw for reception of a rotary tool, and a slug of deformable electric current conducting metal in the set screw bore, to be advanced by rotation of the set screw and dispersed thereby throughout the spaces between the cable strands, for increasing the effective density of that portion of the cable which is within the passageway thereby to effect a tight and solid anchorage and a low resistance electrical connection between the metallic body, the cable strands, and the interspersed deformable metal, and a hard non-deformable sealer disc in the set screw bore interposed between the slug and the advancing end of the pressure screw.

5. In a device of the class described, the combination of a rigid metallic body having a passageway to accommodate a portion of a member to be anchored, said body being bored transversely of the passageway intermediate the ends of the latter, a screw thread formed internally of the bore, a set screw having exterior threads engaging the threads of the bore, said set screw having an axial internally threaded bore and a head exposed externally of the body to receive a wrench, a pressure screw having exterior threads to engage the internal threads of the set screw, a head on the pressure screw accessible exteriorly of the set screw, and a slug of deformable material in the set screw bore to be advanced against the member to be anchored by rotation of the pressure screw.

FRED G. KRUEGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,771,805 Miller July 29, 1930 2,045,547 Chatfield June 23, 1936 2,068,152 Rowe Jan. 19, 1937 2,083,923 Rowe June 15, 1937 

